I don't think I would bother with the middle type lid, unless I had a whole bunch of them. As Tony said, they are really made to just seal once (well, so are this lids on the regular mason jars, but I have not had a problem opening and closing them for "medium term" storage. I would never reuse one for "long term" storage though). But all that being said, because the middle jar has a "pop top" if you heat the jar before putting in the tobacco (which I never bother with), enough that the lid pops down when sealed and cooled, you effectively have a test for the seal; which is the whole point of the poppy thing on top on the first place. So there really is a simple test.....